ABSTRACT/SUMMARY Background: Transgender women are disproportionally affected by substance abuse and HIV. Evidence-based interventions that can address both issues simultaneously may efficiently improve the overall health of transgender women and reduce burdensome health and societal costs associated with substance abuse and HIV. In South Florida, the majority of transgender women identify as Black or Latina, and can be grouped together as transgender women of color (TWOC). TWOC are at highest risk for substance abuse and HIV acquisition, due to multiple external stressors arising as a consequence of being a gender minority and a racial/ethnic minority. Studies have demonstrated Screening, Brief Intervention, and Referral to Treatment (SBIRT) to be effective in mitigating development of substance use disorders (SUDs) in other at-risk, marginalized populations. An adapted culturally-tailored SBIRT focused on linkage to substance use services and HIV pre- and post-exposure prophylaxis (PrEP/nPEP) may effectively reduce the odds of individuals in this special population developing a SUD and also facilitate their voluntary election of HIV screening and use of PrEP/nPEP for HIV prevention. Objectives: K99 ?In preparation for the independent phase, the career development phase will include training in qualitative research methods and intervention development. R00 ? In the independent phase, the study objectives will be to (a) use a mixed-methods approach to obtain formative data among 40 transgender women that will aid in adapting and developing an adapted culturally tailored SBIRT intervention (SBIRT-A), (b) pre-test and refine SBIRT-A in 15 transgender women based on formative work and, (c) pilot test SBIRT-A in a sample of 76 transgender to assess feasibility and acceptability. Pilot Design: Randomized trial among 76 adult (18 years or older) HIV uninfected transgender women at moderate risk for developing a substance use disorder who will be randomized to either SBIRT-A or the control condition (INFO-C). The INFO-C group will be a time-matched comparison control where information will be provided on substance use and PrEP services in a non-SBIRT format via printed and audio-visual study material. There will be a follow-up visit, three months after baseline, to assess linkage, and barriers and facilitators, to substance use services and PrEP/nPEP. Analysis: Bivariate difference tests (chi square and t-tests) will be used to test differences between SBIRT-A and INFO-C participants for the primary outcome measures (linkage to substance use services, PrEP, and nPEP) at the 3-month visit. Multivariate binary logistic regressions (post- and pre-intervention) will be used to determine substance use as a predictor of (1) HIV/STI screening in the past three months and (2 & 3) PrEP and nPEP uptake in the past three months. Significance: Results derived from this study will help elucidate the relationship between substance use and HIV among transgender women, including TWOC, in South Florida, and will provide evidence for a larger study that can test the efficacy of SBIRT-A to reduce prevalence of substance abuse and HIV in this special population. The aims of this study are parallel to the NIH/NIDA strategic plan to decrease HIV/AIDS health disparities, prevent HIV transmission, and better understand the interaction of drug abuse and HIV/AIDS.